The Leaden Thunders Crashed
by TrisakAminawn
Summary: Resistance member Bart Allen accepts his final mission.
1. tumid clouds

**The Leaden Thunders Crashed**

Chapter 1

 _ **A/N:** This should be considered in-continuity with my other YJ!Bart fic, Just Say No, but neither of them requires the other._

* * *

You spent a lot of time alone, when you were the fastest human left alive.

It wasn't that he got _rejected_ for having powers, of course not, no way. Well, just by a few people, but not enough to be important. Ever since he'd gotten his collar deactivated and gone off the grid, he'd been one of the most valued members of the resistance against the Reach, at all of thirteen years old. He was the best courier, the best scout, one of the best thieves, though he liked to call it 'proactive scavenging.' And no one else could do what he could do. No one could keep up.

So he spent most of his time on solo missions, sprinting and hiding and never letting the Reach get a look at him. #478193 was dead; Batman had seen to it. Forward Agent ran like a rabbit and was never, ever caught.

Bart Allen knew the faces of all the most prominent members of the resistance. He knew where to find them. He knew most of their names and most of their secrets. And he'd never betrayed a one. He'd quite cheerfully have died first.

He'd known about the time machine since it was around half-built. He'd stolen or carried most of the sensitive parts at one stage or another, but he hadn't known what they were _for_ until pretty late in the project.

"We should send Allen," Batman had been growling, as Bart scurried into the most secure base he knew of (there _had_ to be ones he wasn't cleared for; anybody could be put on-mode) with a backpack full of scrounged microchips.

The Bat was a big man, which was actually pretty rare these days, with ropes of muscle that would probably have been bulkier if he'd been more willing to call leader's privilege on the protein rations, and ribbons of scars, but he wasn't that old. He only ever wore a mask when dealing with the Reach, but the tattered black cloak he wore all the time was totally practical and kinda crash, so Bart completely endorsed it. It was hard to tell how old a person was for sure, but Batman's hair was mostly still dark and the skin between the scars not totally weathered, and there was no way this was the original Dark Knight, who'd be about eighty and Bart was pretty sure had died off-world anyway. Rumor had it he was the son. Bart had often wanted to ask— _he_ was the Flash's grandson, after all; it was practically a family connection—but he had enough too much information already without getting branded as completely nosy.

Or rather, Batman would only give out necessary information, so there was no point trying. Bart was waiting to catch him in a good mood. (Some of the other scouts told him 'good luck with that,' but Bart was nothing if not an optimist.)

Arriving in the middle of an argument about himself wasn't actually that uncommon. He wasn't attached to any particular cell, but leaders could get possessive, especially of something as rare and tactically valuable as meta agents. _Especially_ the last speedster. Bart had loped over, hoping to hear more. They'd tell him everything he _needed_ to know if they sent him anywhere, probably, but he'd learned never to underestimate the survival value of knowing extra.

"He's vital to the resistance!" Red Condor had snapped back. Bart wasn't sure why she went by Condor, which was apparently some kind of huge extinct bird, but she was the only person who never seemed to back down from Batman. Condors had been bigger than bats, he was pretty sure, but she wasn't that tall. She was somewhere between thirty-five and fifty, had red hair that she kept under a hat to avoid catching attention, and was a master of improvised weaponry. Bart had once seen her take down a fully active Reach patrol 'bot with three rocks and four feet of steel cable.

"Tt." Bart had always been kind of impressed by how scornful Batman could get a single consonant sound. "The resistance does not stand or fall with any one of us, Harper."

"Except you?"

" _Including_ me."

"Oh, saints and stars, was that humility?" Condor rolled her eyes. "The world must have finished ending while I was distracted. That boy is the single most valuable agent we have. You are _not_ treating him as expendable."

"You want me on a suicide run, Bats?" Bart interjected. Keeping his tone light. He wouldn't be the first or the last to run into death with his eyes open for the cause, and while privately he felt Condor had a point about how useful he was, Batman wasn't wasteful. He generally only expended something if he was going to get something more valuable in return, and if he was ready to throw the last speedster away on this, it had to be _big_.

"No," Batman answered curtly. "Harper is being melodramatic."

Well, that was a relief. Bart wasn't excited to die. Life right now was better than it had been since he'd been seven, when the Reach had gotten Dad on-mode and finished off both the Tornado Twins in one blow, and he wanted to do everything and see everything that was possibly worthwhile before he clocked out. Bart knew how lucky he was, to have gotten out, to have these powers and the chance to use them. He'd die, if that was what it took to pass some of that luck around. But doing it sooner than necessary was way too in-line with the mode. "Crash. So what's the mission?"

Condor's face pinched. "Oh, no. You are not doing an end-run around me by getting the boy on board before—"

"If the mission succeeds, we won't _need_ him anymore," Batman interrupted. And okay, now Bart was _really_ interested. What could possibly change the face of the world so much that the resistance had no use for a runner? Some kind of incredibly fine-tuned teleporter? That _would_ be better than him, if they could secure it. No risk of moving through open country, and no problem with walls, and _replicable_ , if it was a machine and not a person. He wondered how fast Batman, Condor, and the tech squad could build bombs, because assembly speed might actually become the only limiter on blowing things up. "So the question is, Harper, do you think the mission is worthwhile, and do you think Allen can handle it?"

Condor flung her hands up without bothering to open her fists. "Your arbitrary conviction that we need to _deceive_ the targets is what's in question!"

"They will not automatically trust a mysterious interloper warning them of an imminent catastrophe. Even if they accept our agent as genuine, our agenda will then be known. It will be subject to criticism, restriction, and doubt from people who do not have the perspective to judge the situation appropriately."

"You are talking about your _own father_ ," exclaimed Condor.

"A great man," Batman acknowledged. "Who _let the world end._ "

Bart couldn't take the time to absorb this perspective on Batman because he had just started to suspect he knew what they were talking about. "Are you building a _real actual time machine?_ "

Okay, so sometimes his mouth was faster than his brain. He blinked again. "And you want _me_ to use it?"

Yes, he was valuable, but he was thirteen. Sensitive missions fell into his lap because his powers made them so much easier, not because he was enormously skilled or brilliant or anything. Short of the machine _needing_ superspeed to work, he didn't see how his name had come up. And if it did, then Condor wouldn't be arguing it shouldn't be him because there wouldn't be anyone else.

"You seem surprised," Condor said, almost smiling, which for her _was_ smiling.

"Well, yeah. I'm...just me, you know?" With an embarrassed smile, he shrugged, making the carefully packed microchips shift but not rattle. He should get those delivered, already, and were they going to be in the time machine? They were absolutely going to be in the time machine. Crash.

"Your completed mission record is longer than those of most agents twice your age," Red Condor told him. Bart hadn't known that, but it made sense. He had an unfair advantage, though. He grinned and tried not to fidget, feeling very on-the-spot.

"And I am told," Batman added, "you are one of our best infiltrators."

No one infiltrated the Reach, of course—you'd need to subvert Reachtech before it could subvert you, for that. But the resistance _did_ have to infiltrate other groups of humans all the time, because the fact was, most people didn't dare stand up to their alien overlords, and a community caught harboring human terrorists…well, it wasn't pretty. For news, for supplies, to position a strike or pass unnoticed through a checkpoint, you needed to be beneath notice. Even someone as striking as Batman could do it, if he needed to. There was a lot of shoulder-hunching, head-hanging, and shuffling involved.

Bart shrugged again. "Only because I look so harmless."

"Precisely," said Batman.

And Bart started to see what he meant.

"Ideally," the commander continued, "we want you on their covert ops first-response team."

Bart fidgeted. "Wouldn't Tre do better, then? Not that I'm trying to get out of the mission! Just…infiltrating a slave camp is different than infiltrating a guard unit." He could tell he was missing something. Batman and Condor had passed on at least a few elements of 'ninja training' to basically everyone in the network, but Tre Hawkins was the best; everyone knew he was being groomed to take over when Batman fell.

"He's too old," Batman replied. Tre was twenty-six. "Their covert strike team was also the junior division."

Wally's team. Wally and Artemis' _Team_ , they wanted him to infiltrate that? Really?

"Also, you have meta powers," Condor interjected. Still not pleased with the plan but clearly aware of its underlying logic. "They won't require you to prove yourself to nearly the same standards as they would a normal human."

Some people would have twisted the 'normal' a little, because most surviving metas were part of the mode these days, and metahumans were the whole reason Earth had fallen within the Reach in the first place, but Condor was just rude. Bart was okay with rude. He grinned.

"Especially," said Batman, "considering your family."

His family was Justice League. Bart knew an in when he…had it explicitly pointed out to him.

"You have that, too," he pointed out in turn. "Uh, sir."

Batman's mouth twitched; Bart wasn't sure if it was amusement or anger or something else. "True, Allen. But I do not look harmless."

Bart heartily agreed. "You've got that right. Okay, then." He gave a sharp little nod, just slow enough for everyone to see, and stood up straight. "Mission accepted."

Condor growled, softly, but she'd already given in, or she wouldn't have been explaining the advantages to him. And really, from what he knew, there really _wasn't_ anyone else.

He smiled. "So…what is the mission exactly?"

"Broadly," Batman answered, with a quelling look at Condor that said he _realized_ there was some debate about the specifications still but this was not the _time,_ "to disrupt the Reach conquest of Earth in its early stages."

Well, yeah. Obviously. "Okay."

"Tt." Apparently Batman found acquiescence annoying. Or he'd seen through the smile to the 'obviously.' "You are aware of the Reach infiltrator known as Blue Beetle." Bart nodded. "At the time of the invasion, he was a member of the covert junior unit."

Bart rocked on his heels, uncomfortable. Taking the Beetle out of the equation would help, of course. Being betrayed by one of their own had always been the thing that most crippled Earth's defenders, whether the betrayal had been voluntary or not. "Uh. I don't think I'm really cut out for assassination, Batman."

"No," Batman agreed. "But you would be capable of it, as a final resort."

Bart dropped his eyes. "Yes, sir."

"Consider the prospect motivation to succeed in your primary mission," the Bat suggested dryly, and Bart ducked his head a little further in acknowledgment.

"First of all," said Condor, "you need to know…"

* * *

 ** _A/N:_** _Tre Hawkins is, incidentally, Virgil's sister's son._


	2. livid lightnings

**The Leaden Thunders Crashed**

Chapter 2

 ** _A/N:_** _Arghle blarghle I thought I posted the second half of this a month ago! Sorry and thanks to everybody! (Especially TaeKwonDoAsskicking, who is the reason I noticed now.) Uh, Merry Christmas?_

* * *

The weirdest thing about preparing for a mission to the past wasn't designing a superhero costume, or practicing smiling _all the time_ , or trying to get ready to be confronted by all that wealth and freedom, or getting an enormous _mountain_ of confidential information drilled into him by Batman, or even the way that information-drilling kept straying amazingly close to a gruff, businesslike version of his Grandma's storytelling. No, it was the food.

Bart _always_ needed to eat more than anyone else. Janet and Fu Li and Ratboy in the scouts complained about his extra rations. Some of the time, he had to carry an active inhibitor collar (with a disabled clasp and transponder, of course) around with him, and wear it when he slept and debriefed and did pretty much anything else that didn't happen at superspeed, just to slow down his metabolism so there was enough to go around.

But most of the time, he was on some kind of mission, and that meant he had to _run_. He got three times normal rations, and made up the rest by scavenging—he was really good at it, because he could get easily to places most people didn't have the time to bother approaching. He even shared out most of the best stuff, which was probably the only reason Ratboy didn't hate him.

Still, he was skinny. His body just didn't have the resources to be anything else. Batman put him on a double-sized high-protein diet for the two months leading up to the mission, and made him do some heavy-lifting work that normally would have been assigned to someone bigger. "The people you're meeting know speedsters," he lectured, with that clipped pattern that came into his voice whenever he wasn't focusing on the way he sounded. Bart wasn't sure why Batman had a problem with his own accent, but given the times he took the trouble to get rid of it, figured it had something to do with being more like the original, who must have spoken differently, even if they were father and son.

"They have expectations about the body type and behavior of someone with your powers. You have to be what they expect. Give them no reason to question. We are taking advantage of a common cognitive error known as the valence effect—most people are more willing to believe things that they find appealing. Therefore, the future is comfortable and safe. History remembers them as heroes. And this outcome depends on their _not_ inquiring into the details. Do not allow the illusion to crack."

Batman—whose name turned out to be Damian, which was one of the few things he _hadn't_ taught Bart on purpose; Bart fully intended to look up the little kid version in the past if he survived the mission, if only for the chance to get away with teasing him, and maybe pay him back for the ridiculous volume of info-mentorship.

Anyway, Batman was way helpful with big-picture stuff, and the detailed secrets Bart would need to strew around to make the heroes of the past eager to shut him up rather than interrogate him, and was just about the only one left who'd actually known any superheroes long enough to have meaningful advice about how they'd worked, for Bart to add to Grandma's stories as he designed his character, while Condor had a lot of tips on infiltration specifics—"Remember you have an excuse to change the subject often," was a good one. "Speedsters are expected to be distractible. Cultivate that."

Which wouldn't be hard. Bart _did_ notice about eighty things a minute, plenty of which were interesting. Staying focused didn't take an effort, exactly, anymore, not so long as there was something important to be focused on, but he wouldn't have to pretend, exactly, either. That went with something he'd kind of known already, but which Red Condor made sure to drive in: Lie as little as possible. _Say_ as little as possible, but never seem mysterious. Be someone trustworthy. That is the heart of a liar.

This provoked a reminder from Batman that everyone trusted the Flashes. That was key to the plan—Bart _had_ to be trusted, underestimated, and allowed near the action, so he _had_ to be on the Team. Superpowers, already knowing everything about them so there was nothing to hide, and something called nepotism was expected to be enough to get him in; if not, he had to follow them around until he got a chance to save someone's life and prove his loyalty and usefulness. A little trickier to pull off without attracting suspicion, but doable.

At this point Batman attempted to lecture him about human tribal tendencies, and Bart left to find Nathaniel, reasoning that if he got in trouble he could say he was practicing being Impulse, who would totally zip off in the middle of a boring lecture. Crash.

"Hey," Bart said as he made a hard right out of a crowded tunnel and zipped up beside the tall bald guy, who almost smiled.

Bart liked Nathaniel. He was quiet and very sincere—he was sad, too, but who wasn't angry or sad sometimes? A lot, even? Nathaniel was adjusting. He'd been one of the first humans the Reach put on-mode, which in his case apparently meant it was like he'd gone to sleep one day, had a long, horrible nightmare, and woken up forty years later to find the world had ended and Batman was mad at him.

He'd told Bart once, only half joking, that the Batman part was so scary it got him past the first horror at everything else. Bart wasn't sure if that had been intentional or not. Batman seemed to know all about head games but not bother with them very much, but the thing was, Nathaniel was Neutron, and 'Neutron' was the supervillain who'd killed the Flash. Grandpa Barry, but to Batman just _The Flash._ (Even though Wally had taken up the name for years, during the early stages of Reach conquest, before they finally got him. Bart wondered whether Batman had known that Flash, as a kid.)

That was the first Reach victory, the beginning of the end, the first thing he had to stop to start setting time right. Bart didn't hate Nathaniel for it, of course—you can't crash the mode from inside, common sense—but sometimes he was pretty sure Batman and Nathaniel kind of did.

They were both really serious people, which might be why, but Bart had a theory that it went with the other main thing they had in common: Batman and Neutron both remembered the world before the Reach. They still didn't really accept that there were times when nothing you did could ever be enough, and that you couldn't _blame_ people for that. You just had to help them past it however you could.

Bart got a lot of hints like that from talking to Nathaniel. He still had his Neutron powers even now that he was off-mode, and had been deployed twice to use them, but his best asset to the resistance right now was as the best living memory of humanity as a free people. The oldsters who were left had all spent more than half their lives under the heels of the bugs, being _meat,_ and they belonged to this time, had changed to survive into it. Nathaniel had seen the changes only from a distance. He _remembered_.

"Hey," Nathaniel responded, setting down the knife he'd been chopping parsnips with. Bart stole a disc of root vegetable as soon as the older guy's eyes left the cutting board, more out of instinct than hunger, because of the aforementioned freakishly giant portions of food he'd been getting, and Nathaniel's eyebrows said that he knew what had just happened even if he hadn't seen it. "Avoiding Batman?"

"He teaches too much theory," Bart shrugged, reaching over to steal another piece of raw parsnip at normal speed, this time. Nathaniel was bad at guarding his _own_ rations, never mind making sure people didn't steal while he was on mess duty; Bart had no idea why he was allowed to cook. No one let Bart cook. "I have a good memory but there is a limit."

"Hm," Nathaniel agreed, going back to chopping, like that was any deterrent to someone with Bart's speed. Back when Nathaniel first joined them, Bart had stolen so much of his food so often that he'd started getting faint from undernourishment.

Tre had been the one to figure it out, and talked very seriously to Bart before giving him punishment duty for carelessness endangering a comrade, and for abusing his powers, but he hadn't actually _had_ to abuse them because Nathaniel had never tried to _stop_ Bart companionably scavenging off his plate. Looking back, it had probably been a guilt thing—he'd maybe even thought Bart was punishing him, which made Bart feel practically moded himself when he thought about it too hard—but Bart had really just thought the guy wasn't hungry, because he hadn't acted defensive over his food at all until he was literally starving. It was like he didn't even have the instincts for hunger.

The past was going to be so weird.

Three weeks before departure time, Bart caught Condor looking at him funny while she recounted something she'd once heard about the second Flash, Bart's cousin Wally. (Who it turned out had been related to Condor's mom by marriage, how crash was that? Family! That was alive! He didn't try to hug her or anything, but it was pretty cool.) It was a soft sort of look, that seemed to go with the way she, like Batman, kept including details that couldn't possibly be useful with odd emphasis, and that night he finally figured it out, and felt like the slowest boy alive.

This wasn't a suicide mission, unless the machine broke in a particularly catastrophic way. This was a mission where the _goal_ was to be _the only survivor_.

There were people in the world older than forty, but with the cullings, not that many. Most of the people Bart had _ever_ known who'd been alive forty years ago were dead now. He was pretty much setting out to kill everyone alive. No, not kill. Unmake. _Uncreate_ his whole generation and most of the one before it.

After a night of tossing and turning, he took his shift on dawn watch. Ratboy, who was his partner because neither Batman or Condor was the kind of cell leader who took personal preferences into consideration when drawing up a roster, demanded to know what the hell was wrong with him, and Bart answered a little too willingly, "If it would save the world, would you be okay with never being born?"

Ratboy spat. "World like this? Like it's worth saving."

He risked his life for the resistance all the time, jerk or not, but that wasn't the world, not really, that was _people._ Their people. People Bart was going to kill. "But if we could go back and crash the mode before it started, so the Reach never won," he said. "Your parents might never meet. They might never even be _born_. Would that be okay?"

Tre would say yes, but Tre was a hero. Tre was brave and kind and completely ready to die. Ratboy was an angry, mean survivor. If _he_ said yes…

He snorted. "You and your what-ifs, you walking stomach. Some of us don't have powers, can't afford to play pretend."

"Just if, though," Bart insisted, and Ratboy looked at him a little funny, and he knew he'd been too intense. He was giving too much away. But then, didn't people deserve to know? If they were going to destroy them all, for this plan. Didn't they deserve to have some kind of say? They couldn't ask everyone, because then the Reach would find out, and Batman and Condor wouldn't let public opinion affect their planning anyway, but if he could get a response from someone as bitter as Ratboy, that would mean something.

And then a Reach patrol hit the perimeter and they had to move, move, _move._

Later, after they'd made sure no transmissions had gotten through and finished putting out the grassfire, Ratboy sidled up to Bart and looked at him slantwise, like he looked at most things. "Yeah."

"Huh?" Bart looked up from rubbing soot off his hands, clueless.

Ratboy rolled his eyes. "What you were asking earlier. This world is moded shit. If we could have something better, let it burn."

"Even if—"

"Yeah, even if it means I never existed. Whatever."

Bart grinned, and Ratboy definitely knew something was up, but he didn't ask, and he didn't gossip.

The drilling got harder and harder as the machine neared completion. And it turned out it wasn't just Batman and Condor; people who knew about the plan kept slipping up to him in odd moments and telling him things, tiny things, mostly, that had nothing to do with the mission.

Advice, sometimes, or stories about their lives, sweet things and angry things and accounts of particularly important battles and heroic sacrifices Bart hadn't witnessed, that would soon never have happened if he did this right. _Stop_ , he wanted to tell them sometimes, when the weight of whatever they were entrusting was particularly large and he could feel it, threatening to weigh him down and make him slower. But he never did, and every time he didn't say it, he was glad after that he hadn't. Is glad, still.

He's going to have the whole future on his shoulders, whether he knows all the details that add up to the one he's leaving behind or not. Whether he remembers for them or not. He can't _let_ it be too heavy. He can't let himself be too small to hold it. He's going back to save the past, and his memory is all he can offer the present.

And now. Now it's time. Now he's here in the ruins of a mountain once called Justice, torn down by treachery, ready to go back to when it was whole. Here beside the machine that he and Nathaniel carried here in pieces and assembled on the spot, and if either of them made a mistake it could mean disaster, but they didn't. He trusts them both.

Now Bart smiles grimly at Nathaniel, and opens the time machine, and doesn't think about who might be getting killed in the distraction Batman's staging further up the coast, because it doesn't really matter anymore. He thinks about heroes, instead. About how much he loves the idea of them. How much they gave, how much they're still giving. About sacrifice and hope and making a future worth protecting. About second chances for Grandpa and Nathaniel and Red Condor and Blue Beetle and everyone who'll still exist when this is over. He rolls his shoulders, and settles into character.

He appreciates all the training. He really does. Everything he's gotten from everyone. They've given him all kinds of tools to make this easier, and more importantly, they've given him their memories. But really, what he's going to need to do is wait for the right moment, and run. And smile. And pretend everything is fine. And he's going to do it alone.

Bart has been training for this mission his _entire life_.


End file.
